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Hole migration and optically induced charge depletion in GaSb/GaAs wetting layers and quantum rings

We present the results of photoluminescence (PL) measurements on a type-II GaSb/GaAs quantum dot/ring sample as a function of temperature (2 to 400 K) and over six orders of magnitude of incident laser excitation power. Optically induced charge depletion (OICD) was seen in both the wetting layer (...

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Main Authors: Hodgson, Peter D., Young, Robert J., Ahmad Kamarudin, Mazliana, Zhuang, Qian Dong, Hayne, Manus
Format: Article
Language:English
English
Published: American Physical Society 2013
Online Access:http://psasir.upm.edu.my/id/eprint/30304/1/Hole%20migration%20and%20optically%20induced%20charge%20depletion%20in%20GaSb.pdf
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spelling oai:psasir.upm.edu.my:30304 http://psasir.upm.edu.my/id/eprint/30304/ Hole migration and optically induced charge depletion in GaSb/GaAs wetting layers and quantum rings Hodgson, Peter D. Young, Robert J. Ahmad Kamarudin, Mazliana Zhuang, Qian Dong Hayne, Manus We present the results of photoluminescence (PL) measurements on a type-II GaSb/GaAs quantum dot/ring sample as a function of temperature (2 to 400 K) and over six orders of magnitude of incident laser excitation power. Optically induced charge depletion (OICD) was seen in both the wetting layer (WL) and quantum dots/rings but with remarkably different temperature dependent behavior. Holes originating from background acceptors migrate out of the WL as the sample temperature is raised to 30 K, while the onset of a blueshift in the PL from quantum rings, signaling their thermally induced charging with holes, is only observed at temperatures above 300 K. The presence of dark dots as a hidden reservoir for acceptor holes at the intermediate temperatures is proposed to explain this anomalous behavior. Due to the deep localization potential of GaSb/GaAs, thermalization of acceptor holes between dark dots and bright rings only occurs above room temperature. A rate equation model is presented which successfully replicates the main features of OICD observed here and in previous reports American Physical Society 2013 Article PeerReviewed application/pdf en http://psasir.upm.edu.my/id/eprint/30304/1/Hole%20migration%20and%20optically%20induced%20charge%20depletion%20in%20GaSb.pdf Hodgson, Peter D. and Young, Robert J. and Ahmad Kamarudin, Mazliana and Zhuang, Qian Dong and Hayne, Manus (2013) Hole migration and optically induced charge depletion in GaSb/GaAs wetting layers and quantum rings. Physical Review B: Condensed Matter and Materials Physics, 88 (15). art. no. 155322. pp. 1-7. ISSN 1098-0121 10.1103/PhysRevB.88.155322 English
institution UPM IR
collection UPM IR
language English
English
description We present the results of photoluminescence (PL) measurements on a type-II GaSb/GaAs quantum dot/ring sample as a function of temperature (2 to 400 K) and over six orders of magnitude of incident laser excitation power. Optically induced charge depletion (OICD) was seen in both the wetting layer (WL) and quantum dots/rings but with remarkably different temperature dependent behavior. Holes originating from background acceptors migrate out of the WL as the sample temperature is raised to 30 K, while the onset of a blueshift in the PL from quantum rings, signaling their thermally induced charging with holes, is only observed at temperatures above 300 K. The presence of dark dots as a hidden reservoir for acceptor holes at the intermediate temperatures is proposed to explain this anomalous behavior. Due to the deep localization potential of GaSb/GaAs, thermalization of acceptor holes between dark dots and bright rings only occurs above room temperature. A rate equation model is presented which successfully replicates the main features of OICD observed here and in previous reports
format Article
author Hodgson, Peter D.
Young, Robert J.
Ahmad Kamarudin, Mazliana
Zhuang, Qian Dong
Hayne, Manus
spellingShingle Hodgson, Peter D.
Young, Robert J.
Ahmad Kamarudin, Mazliana
Zhuang, Qian Dong
Hayne, Manus
Hole migration and optically induced charge depletion in GaSb/GaAs wetting layers and quantum rings
author_facet Hodgson, Peter D.
Young, Robert J.
Ahmad Kamarudin, Mazliana
Zhuang, Qian Dong
Hayne, Manus
author_sort Hodgson, Peter D.
title Hole migration and optically induced charge depletion in GaSb/GaAs wetting layers and quantum rings
title_short Hole migration and optically induced charge depletion in GaSb/GaAs wetting layers and quantum rings
title_full Hole migration and optically induced charge depletion in GaSb/GaAs wetting layers and quantum rings
title_fullStr Hole migration and optically induced charge depletion in GaSb/GaAs wetting layers and quantum rings
title_full_unstemmed Hole migration and optically induced charge depletion in GaSb/GaAs wetting layers and quantum rings
title_sort hole migration and optically induced charge depletion in gasb/gaas wetting layers and quantum rings
publisher American Physical Society
publishDate 2013
url http://psasir.upm.edu.my/id/eprint/30304/1/Hole%20migration%20and%20optically%20induced%20charge%20depletion%20in%20GaSb.pdf
_version_ 1819295309777338368
score 13.4562235

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